Tool Maker Keeps Pace With Design Progress
Page 25
If you've noticed an error in this article please click here to report it so we can fix it.
Modern Vehicles Need Up-to-date Equipment for Servicing and Maintenance. Black and Decker, Ltd., is a Specialist in Portable Electric Tools for Such Purposes. We Review Some of Its Latest Products
ARAGE equipment is contimiously Is.-lbeing remodelled and redesigned as new inventions, methods of construction and metals are applied in the manufacture of commercial vehicles, As one example, we may cite the trend towards the use of valves with hardalloy heads. When servicing it was found that the older-type dry-grinding refacers were inadequate to deal with all the valves encountered when maintaining large fleets of vehicles and when a variety of engines was reconditioned.
It was with that in mind that Black and Decker, Ltd., Hannondsworth, Middlesex, designed the wet-grinding Valve Master refacer. This machine gives an accurate mirror finish, as the coolant ensures even temperature when grinding, eliminating distortiop, whilst the finish is not affected by variations of the grinding speed due to different diameters of valve heads.
-A feature of the Valve Master is the ingenious design of the wet-grinding unit. The liquid is contained in a reServoir at the back of the machine, and, .after passing through a. filter, is pumped on to the grinding wheel. A
patented jet allows only a thin film to impinge On the wheel, thus eliminating wastage and splashing. This jet is easily removable for cleaning purposes. A special lip collects any liquid which may drop off the valve head. The grinding spindle is provided with beatings of new design which makes possible an exceptionally close fit. They are of the self-aligning, spring-loaded and oil-impregnated type.
Other new features of the Valve Master include a method of supporting the work table by self-aligning nickelchrome-iron bearings, which give smooth finger-tip control to the feed, a quick-lead, self-aligning feed screw, combining the speed of a lever feed with the precision of a screw feed, and an automatic belt-stretch adjustment with shock-absorbing device, ensuring vibrationless running of the wheel.
A necessary companion to the Valve Master refacer is the Vibro-Centric valve-seat grinder.
Like the Valve Master, it was introduced primarily to 'deal with modern valve seats, whether of cast iron, alloy steel, or Stellite, A positive vibrating device, built into the spindle of the driver, lifts the stone from the seat once each revolution, clearing the stone by centrifugal force.
Grinding is concentric and cuts the entire circumference at once; the speed being 12,000 r.p.m. Little metal is removed, practically eliminating the necessity of narrowing. All seats are ground dry; no lapping is needed.
Another Black and Decker tool of recent introduction is the 7-in, combi nation sander _ polisher, specially designed for repair departments having an intermittent need for a sander and a polisher, but using neither on constant production service. In addition to handling all general metal-surfacing operations with 7-in, discs at 4,200 r.p.m., it can be used at 1,300 r.p.m., the correct speed for polishing and rubbing-down cellulose.
Novelty also attaches to this portable-electric-tool specialist's Lectro Shear, available in two sizes, for 18 or 16-gauge material. The shearing action is accomplished by the rapid reciprocating action of a vertical blade against a stationary horizontal blade, set in a special shoe, which gives the correct cutting angle and adapts the tool to all types of cutting work.
It will cut on a radius as small as in., and will easily follow a straight, curved or irregular line.